The present invention relates generally to a method of making metal nanoparticles and, more particularly, to a method of making metal nanoparticles from mesityl precursors.
Synthesis of coinage nanoparticles (NP) has been available for over a century but control over their size and monodispersity had not been realized until recently. Research in this endeavor has focused on the synthesis, ordering, and properties of coinage-metal NP due to the dependence of the NP optical properties on the shape and size of the NP. This phenomenon is attributed to the particularly strong surface plasmon oscillations within these metals.
Salt reduction methods have been used in the formation of Group 11 (copper, silver, and gold) NPs. In one method, two-phase reduction of AuCl4−by NaBH4 has been used to afford mono-dispersed 3 nm gold particles passivated by nonanethiol. This method is widely employed to synthesize monodisperse gold, silver, and copper oxide coated copper NPs. These are often stabilized by a number of passifying agents, including alkanethiols, phosphanes, quaternary ammonium salts, surfactants and polymers. However, current synthesis methods typically require complex starting materials, reducing agents and special additives (such as detergents), and produce salts or other difficult to remove by-products. Current methods also typically require multi-step “seed-growth” steps followed by post-synthetic purification techniques to generate coinage-metal NPs of various sizes.